The present invention relates to a substrate treating apparatus for use with glass substrates (base plates) for liquid crystals and photomasks, etc. on the surfaces of which thin films such as of a photoresist coating solution, a photosensitive polyimide resin and dyestuffs for color filters are to be formed. The apparatus supplies a given treating liquid to the principal planes of those substrates for desired treatment.
There has been known as a conventional technology of a substrate treating apparatus wherein a substrate having been subjected to certain treatment in the preceding step is carried to the next step after being cleaned with a cleaning chemical. Such a substrate treating apparatus generally comprises an apparatus body including a chemical cleaning station, a water cleaning station and a drying station arranged in series, and substrate carrying means provided to extend through the chemical cleaning, the water cleaning and the drying stations.
Conventionally, the carrying means is designed to carry a substrate in a horizontal posture and the substrate is treated while being carried by the carrying means through the chemical cleaning station, the water cleaning station and the drying station of the treating apparatus body in the named order. Specifically, a chemical cleaning process is first performed on the substrate, transported into the treating apparatus body, in the chemical cleaning station by supplying a given chemical to the front and rear surfaces of the substrate. Then, after removing the chemical, a water cleaning process is performed on the substrate in the water cleaning station. Finally, a drying process is performed in the drying station by, e.g., spraying gas to the substrate.
When the substrate is carried from the chemical cleaning station to the water cleaning station, it is moved toward the water cleaning station while the chemical on the substrate is removed by an air knife or the like, so that the chemical and the cleaning water are prevented from mixing with each other on the substrate. In the water cleaning station, a finish cleaning process is usually performed on the substrate as a final step using pure water. At this time, water wiping is also performed by an air knife or the like so that the usual cleaning water on the upstream side and the pure water on the downstream are prevented from being mixed with each other on the substrate.
Meanwhile, it has been recently proposed to carry a substrate in an inclined posture through the treating apparatus body. With this proposal, the treating liquid supplied to the substrate flows down fast over the substrate slopes and is diminished quickly. Therefore, the treating liquid on the upstream side and the treating liquid on the downstream side are surely prevented from being mixed with each other on the substrate, and hence the liquid removing step using an air knife or the like can be dispensed with. This contributes to a reduction in the equipment cost.
However, because the substrate is carried into an inlet of the treating apparatus body in a horizontal posture and discharged from an outlet of the treating apparatus body to the next step in a horizontal posture, it is required not only to automatically change the posture of the substrate having been carried in the horizontal posture to an inclined posture upstream of the treating apparatus body for transfer to the carrying unit in the treating apparatus body, but also to automatically return the substrate from the inclined posture to the original horizontal posture downstream of the treating apparatus body. Unless the technique realizing the requirements is established, the above proposal of cleaning the substrate while carrying it in the inclined posture through the treating apparatus body, cannot be applied to the practical use. Nevertheless, that technique has not yet been established at the present.